Is Cryo Treatment Worth It for Rear Rotors?

[dmw16]

Heading into my first track season I'm pretty much set on buying a set of blank rear rotors since I've heard that the E46 ZCP drilled rotors aren't great for track duty.

Tirerack has plain blanks for $58 each and cryo treated blanks for $82. Is there any real benefit for track applications to the cryo treated rotors?

[Porschefile]

I wouldn't bother for rears, rear brakes last forever. There is at least some evidence that cryo makes rotors last longer, but for rear it is not necessary.

[dmw16]

Originally Posted by Porschefile

I wouldn't bother for rears, rear brakes last forever. There is at least some evidence that cryo makes rotors last longer, but for rear it is not necessary.

So is this a case where I shouldn't even worry about my rear rotors? I am just suspect of the ZCP rotors and they are about 2mm over min-spec thickness. I'd hate to have them warp and then be in a pinch of needing new ones at the track.

[Porschefile]

Never owned a E46, but I can tell you that I left the stock rears on my E92 even with Stoptech bbk up front and it works great (and I'm hard on brakes). I would change pads to stoptech street performance or real race pads though.

[dmw16]

Originally Posted by Porschefile

Never owned a E46, but I can tell you that I left the stock rears on my E92 even with Stoptech bbk up front and it works great (and I'm hard on brakes). I would change pads to stoptech street performance or real race pads though.

Thanks for the info.

I bought a Stoptech ST40 355mm front kit and bought PFC01 pads for the front and back.

For $135 for a set of regular blank rear rotors I decided it's worth the peace of mind to know that if my ZCP rear rotors warp I have a set of new ones in my track tool kit.

[CanAutM3]

I tacked my E46 for 7 years and only needed to replace the rear rotors once. I was using stock rotors. I would not worry.

[ThunderMoose]

Rear rotors will be fine. Most people claiming to have "warped" rotors actually have uneven pad deposit which can be corrected relatively easy with re-bed when pads are cold and abrasive.

I replace my pads on the front 3 times for every rear pad replacement, which is another way to say rears should be fine.

This is for E46 M3 with pagids and slotted rear rotors.

[Vic311]

Cryo rotors are a scam.

[dmw16]

Thanks again everyone for all the info.

I ended up getting a set of regular blanks for the rear for $135 to replace my ZCP rotors which have a decent amount of miles on them. For that amount of money I figured I can't really go wrong and I'm glad I didn't spring for the cryo treated ones.

[maxenar]

Originally Posted by dmw16

Thanks again everyone for all the info.

I ended up getting a set of regular blanks for the rear for $135 to replace my ZCP rotors which have a decent amount of miles on them. For that amount of money I figured I can't really go wrong and I'm glad I didn't spring for the cryo treated ones.

Great choice!! There is statistical evidence showing that cryo rotors last slightly longer than non-treated ones. But it's definitely not worth the extra coin..

[Raucky2000]

Skip the deep freeze IMO...spend the money on something else...like food/water at the track so you don't BONK and wreck your car! That's money very well spent...IMO.